Hi Paul,
sorry not to have been back, football and trying to save our club's name got in the way.
I really like the Leave it out bits, they may not have any oomph but they provide a contrast with the music and the rest of the vocals. They hang back as the music's hurtling forward, reinforcing what the song is about. They also sound like a second voice, which, of course, they are.
If you made them similar to the rest of the vocal the contrast would disappear and so would some of the dark and light, to the detriment of the song, in my opinion.
Feel free to ignore if you disagree.
diadem